The US and China have been discreetly engaging in “war games” amid rising anger in Washington over the scale and audacity of Beijing-co-ordinated cyber attacks on western governments and big business, the Guardian has learned.

State department and Pentagon officials, along with their Chinese counterparts, were involved in two war games last year that were designed to help prevent a sudden military escalation between the sides if either felt they were being targeted. Another session is planned for May.

Though the exercises have given the US a chance to vent its frustration at what appears to be state-sponsored espionage and theft on an industrial scale, China has been belligerent.